The trigger looks good.
I just have one question: How do you want to set slide = true? It is difficult to create a region and use "Unit leaves region ..." because a hero could walk the way back and so he leaves the region when he still is on the normal path.
This is the main reason why I used in my trigger the "Terraintype = ..." conditions.
And, as I said, you'll need thousands of regions with "Unit enters region ...", to kill the hero when he walks off the path.
And I noticed one thing:
As far as I remember, you had 11 player slots.
An example: Slots 1 to 7 are full, 8 is empty and 9 to 11 are full.
So you get 10 players. You set the array for players 1 to 10. Now you have a problem. You forgot player 11 and used player 8, which is not used.
I don't know, how you are setting the array, but this problem could occur if every player (unused or not) has a slot.